biomed Q1 summative

Pedigrees and Genetics:’

What does it mean if a trait is autosomal recessive?

two copies of the gene are needed for the trait to appear

How does homozygous dominant differ from heterozygous when considering autosomal recessive traits?

Homozygous dominant has two dominant alleles and expresses dominant phenotype. heterozygous has one dominant and one recessive.

How does homozygous recessive differ from homozygous dominant?

Homozygous recessive expresses the recessive trait, homozygous dominant expresses the dominant phenotype

How does an antigen differ from an antibody in terms of function and location within an organism?

an antigen is a foreign molecule that triggers an immune response, an antibody is a protein made by immune system that binds to an antigen

How do antigens and antibodies interact in the immune response?

antibodies specifically bind to antigens, forming a signal to the immune system to destroy invader

What is the role of B-lymphocytes in the immune response?

they produce antibodies, key part of adaptive immunity

During an ELISA test, how does a primary antibody differ from a secondary antibody? What role does each antibody play in the test?

the primary antibody binds directly to antigen, secondary antibody binds to the primary and is linked to an enzyme that produces a color change

What is the role of the color substrate in the ELISA test? What does a color change indicate?

The color substrate reacts with the enzyme to produce a color which indicates an antigen is present

What is the purpose of running an ELISA test?

What is the purpose of performing a serial dilution in conjunction with an ELISA test?

to detect and measure the presence of an antigen or antibody

What is the role of a plasmid in bacterial anatomy?

circular DNA that carries extra genes, such as antibiotic resistance, which can be shared

How does bacteria stick to other surfaces to aid in its pathogenicity?

using pili

What structure do bacteria use to move within the host organism?

flagella

How does a cell membrane differ from a cell wall and the capsule in terms of function within a bacterial organism?

cell membrane controls what enters/exits, cell wall provides structure , capsule helps avoid immune detection and aids attachment.

How does a bacteria transfer resistance genes through the process of conjugation?

DNA are transferred directly between bacteria through a pilus

What is required to happen to an antibiotic resistant bacteria to transfer its resistance via transformation?

a bacterium takes up free DNA from environment, DNA must integrate into its genome

What outside “vehicle” is needed for a resistance gene to be transferred via transduction? How does this “vehicle” move the genetic material from one bacterium to another?

a bacteriophage carries DNA from one bacterium to another. The virus injects the DNA into the new host.

Why are beta-lactams, such as penicillin, effective against most non-resistant bacteria? (Think about what beta-lactams target).

They target bacterial cell wall synthesis, causing the wall to weaken and cell to burst

Why do beta-lactams not kill human cells while targeting bacterial infections?

Humans don’t have cell walls

Why is it important to take the full prescribed dose of an antibiotic when fighting a bacterial infection?

to ensure all bacteria is killed

What two categories of antibiotics are considered bacteriostatic in their effect? What is the difference between bacteriostatic and bactericidal in terms of the effect on bacteria?

Bacterioastic- stops growth (tetracyclines, sulfonamides)

bactericidal- kills bacteria

Explain what happens to someone who is allergic to penicillin when they take a penicillin based antibiotic?

the immune system mistakenly identifies penicillin as harmful—> triggers an allergic reaction

How does salmonella cause diarrhea?

salmonella infects intetsinal cells, causing damage—> fluid release

How does osmosis play a role in the watery nature of the stool in someone with a salmonella infection?

water moves into the intestines due to high solute concentration → watery stool.  Toxins cause tissues to pump out solutes, causing an osmotic imbalance

What is the role of the immune system in fighting an infection of salmonella bacteria?

WBC attack bacteria, causing inflamtiom and helping eliminate infection

How do bacteria differ from viruses?

Bacteria are living cells and can reproduce independently. Viruses are non-living, and require a host to reproduce.

Why do antibiotics not typically work to kill viruses? For example, why are beta-lactams and tetracyclines ineffective against the viral common cold?

antibiotics target bacterial structures that viruses lack

What are three mechanisms used by bacteria to resist antibiotics?

Resistance Mechanisms: Drug inactivation, target modification, efflux pumps, biofilm formation.

How do bacteria, such as Staphylococcus aureus, become resistant to most antibiotics?

S. aureus Resistance: through Mutations or gene transfer of resistance genes via plasmids or other bacteria. 

What role do healthcare professionals play in slowing the spread of superbugs?

prescribe antibiotic responsibly, educate patients, monitor infections, enforce hygeine

What is another name for the ear drum?

Tympanic membrane

What is another name for the outer part of the ear (the one attached to your head)?

pinna

What is the role of the bones in the middle ear in regards to sound?

middle ear bones(malleus, incus, stapes) amplify and transmit sound vibrations to inner ear

How are soundwaves transformed into electrical signals in the cochlea?

cochlea function: hair cells convert vibrations into electrical signals

What is the purpose of the auditory nerve?

carries electrical signals to brain for interperation

Why are cochlear implants necessary in patients with severe hearing loss?

bypass damaged hair cells and directly stimulate the auditory nerve, allowing sound perception

Study serial dilutions and pedigrees

-dilution factor is 13

-pedigree is 4 and 5